Production of hydrogen for fuel cell: modeling of a bioethanol microreformer coupled to a PEMFC

Microchannel reactors are miniaturized chemical reactions systems which contain reaction channels with characteristic dimension in the range of 10-500 μm. One possible application for microchannel reactors is the production of hydrogen used in fuel cells to generate electricity for portable equipment. In this paper, we propose to model a microchannel reactor that produces H₂ from the reaction of steam reforming of bioethanol. A microchannel reformer is coupled to a hydrogen fuel cell (PEM fuel cell) microstructured that consumes H₂ while it is being produced by the reaction of reform. The interface between the PEM fuel cell and the microreformer is made by a hydrogen-permselective membrane. The produced hydrogen permeates through this membrane, ensuring a source of high-purity hydrogen that can be directly utilized in a PEM fuel cell. In addition, the hydrogen removal from the reaction zone by its flow through the membrane dislocates the reaction towards the formation of greater yields of hydrogen. The modeling of this system that operated with an electric potential difference of 0.4 V, resulted in the production of 4.41 mol H₂ per mol of ethanol fed into the microreformer. 75.58% of all the H₂ produced was consumed by the PEM fuel cell, generating an electric power of 0.12 W per microchannel. Thus, a device containing 225 microchannel generates an electric power of 27 W, and has approximate dimensions of 3 x 3 x 3 cm³ with the advantage of rapid charge by simply completing the compartment reserved for ethanol.